The present invention relates to a method for transferring voice messages.
The present invention also relates to a communication network.
For telecommunications different types of communication networks are utilized, adapted to different usage areas. Existing public telephone networks are mostly intended for transfer of analog, continuous signals while other networks are designed for high speed transfer of digital data signals. Pager systems and radio networks for data transfer to mobile terminals such as MOBITEX.RTM. (registered trademark belonging to Televerket) are examples of a type of network that is primarily meant for low speed transfer of digital data.
In mobile telephone systems of the cell type (for example the Nordic NMT, GSM and the like) it is of course possible to transfer voice messages. The transfer in the network is connectivity oriented, which means that a fixed connection route exists for the transfer between the caller and the receiver.
MOBITEX.RTM. on the other hand, as with many other data networks, is a packet-switched data network, i.e. a network where data from different sources are brought together in "packets" which are split up after transfer through the network. By means of the packet-switched network, the connections can be used simultaneously by several users with different addresses. It is therefore impossible to transfer voice messages in these networks in real time from, for example, within the network or a public telephone. To send messages, a message that is to be transferred has to be written in at a terminal, after which the message is queued for transfer as a batch in the same manner as other data.
As the access to terminals with connection possibilities to said networks is limited, it is in practice difficult for the public to utilize radio networks such as pager systems and MOBITEX.RTM. for transfer of voice messages to and from mobile terminals (which are not usually equipped for voice input and output). If this could be made possible, a new market within telecommunication would be made available.
The object of the present invention is thus to provide a method and a telecommunication network through which it is possible to transfer voice messages primarily bi-directionally in a packet-switched narrow band radio data network between terminals of the packet-switched narrow band radio data network or between a public telephone network and terminals of the packet-switched narrow band radio data network.